From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx172.postini.com [74.125.245.172]) by kanga.kvack.org (Postfix) with SMTP id AF9F66B005C for ; Mon, 9 Jul 2012 08:01:24 -0400 (EDT) Date: Mon, 9 Jul 2012 14:01:21 +0200 From: Michal Hocko Subject: Re: [PATCH] mm/memcg: return -EBUSY when oom-kill-disable modified and memcg use_hierarchy, has children Message-ID: <20120709120121.GB4627@tiehlicka.suse.cz> References: <1341485708-14221-1-git-send-email-liwp.linux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1341485708-14221-1-git-send-email-liwp.linux@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Wanpeng Li Cc: Andrew Morton , Johannes Weiner , KAMEZAWA Hiroyuki , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu 05-07-12 18:55:08, Wanpeng Li wrote: > From: Wanpeng Li > > When oom-kill-disable modified by the user and current memcg use_hierarchy, > the change can occur, provided the current memcg has no children. If it > has children, return -EBUSY is enough. I do not think EBUSY makes any difference. I would much rather see the test go away... > Signed-off-by: Wanpeng Li > --- > mm/memcontrol.c | 7 +++++-- > 1 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 63e36e7..4b64fe0 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -4521,11 +4521,14 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp, > > cgroup_lock(); > /* oom-kill-disable is a flag for subhierarchy. */ > - if ((parent->use_hierarchy) || > - (memcg->use_hierarchy && !list_empty(&cgrp->children))) { > + if (parent->use_hierarchy) { > cgroup_unlock(); > return -EINVAL; > + } else if (memcg->use_hierarchy && !list_empty(&cgrp->children)) { > + cgroup_unlock(); > + return -EBUSY; > } > + > memcg->oom_kill_disable = val; > if (!val) > memcg_oom_recover(memcg); > -- > 1.7.5.4 > -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org